Bouncing Ball Lab 2019 - In class worksheet PDF

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Bouncing Ball Lab (3/13/19)

Graph 1. Position vs. Time of a Bouncing ball

Graph 2. Velocity vs. Time of a bouncing ball

Graph 3. Height vs. Time of a Bouncing Ball

Graph 4. Potential Energy, Kinetic energy, and Mechanical Energy

1) Describe how you calculate h(t) To find h(t) you need to calculate the distance from the stool to the motion sensor and then subtract the height of the motion sensor from the position of the ball relative to the motion sensor. This will give you the height of the ball with respect to time 2) Compare the shapes of the two energies. Based on your graph, what is the ball doing when K(t) is at a peak? WhenKinetic Energy K(t) is at its peak the ball has just hit the stool. This also occurs when the ball has its lowest potential energy. The ball has its peak potential energy when it has its maximum height value. This makes sense when considering it in relation to the formula for potential energy with respect to height

3) In your calculations, 𝑈 = 0 when the ball is against the bouncing surface. How would your energy plots change if you define 𝑈 = 0 at a different height? (e.g. the starting height, the floor, the ground outside, etc) If you were to change the position at which you considered potential energy to be zero, the graph of potential energy would simply shift up or down relative to where you choose to arbitrarily make U = 0. If you were to choose to have U = 0 at the ground the graph of potential energy would just shift upward along the y-axis proportional to mg x ([delta] H).

4) Across your whole plot, is Mechanical Energy 𝐸 conserved? If not, are there parts of  raph where energy is conserved? Describe these points in terms of the your 𝐸 vs. time g plot and what the ball was doing during those times. Mechanical energy is not conserved in the system. Although it is not, there seems to be places in the graphs where the mechanical energy is, indeed, conserved. There is loss of the mechanical energy from every drop but there is still a peak. This peak comes from the elastic potential energy being stored when it hits the ground and then being released afterwards.

 raph where 𝐸 goes to 0. Is energy 5) You should observe several points on the 𝐸 vs. time g really disappearing? Where does the energy go at this point? How does it come back? The energy is not really disappearing but it is being converted into elastic potential energy. 6) From your data, what is 𝐶r for the basketball? Is 𝐶r the same for each bounce? If not, explain what could cause this. r is not the same for each of the balls that we bounced. This is because each of the balls is made of different materials and thus the energy that is lost in the friction of each of the balls compressing when they hit the chair is different. This causes different loses in Mechanical energy between the balls, and as a result difference in height between the balls. 7) What are your measured 𝐶r values for each ball? Compare the physical attributes of each ball and their relative 𝐶r values. The balls with the highest Cr values were the ones who had the most elastic nature, meaning that they return to their non-compressed form in the fastest time. The most elastic balls were the Lacrosse ball and the Basketball. It then makes sense, that these balls had the highest Cr values. The Pink ball was the most elastic behind these two followed by the Tennis and the Baseball. The Baseball had the lowest Cr value because it was the least elastic of all the five balls. Thus, it makes complete sense as to why it has the lowest Cr value.

8) In a brief paragraph, summarize this lab. You should include a summation of the major themes of the lab, as well as brief descriptions of your procedures, analytical methods, all relevant quantitative results, and your conclusions. Also, check that all graphs are included and your report is in the correct order. This lab showed us the properties of Mechanical, potential, and kinetic energy and how they are converted from one type to another. In this lab, we observed the conservation of energy when only conservative forces are acting on the object. In this case, that object is the ball. Additionally, we observed the dissipation of energy when non-conservative forces were acting on the object (the ball). In addition to our observations, we learned how to understand how energy can be transferred from one form to another. Namely, mechanical energy to elastic potential energy and then back....